Display system with distributed led backlight

ABSTRACT

A display system with a distributed LED backlight includes: providing a plurality of tile LED light sources, each tile LED light source having a tile and a plurality of similar LED light sources on each tile connected for emitting light therefrom; orienting the plurality of tile LED light sources for illuminating a display from the back of the display; and integrating the plurality of tile LED light sources into a thermally and mechanically structurally integrated distributed LED tile matrix backlight light source.

RELATED APPLICATIONS

This is a continuation of U.S. patent application Ser. No. 12/237,331,filed Sep. 24, 2008, which claims priority under 35 USC 119(e) to U.S.Provisional Application No. 60/976,404, filed Sep. 28, 2007, the entirecontents of which are hereby incorporated in their entirety.

TECHNICAL FIELD

The present invention relates generally to display systems, and moreparticularly to a display system with a distributed LED backlight.

BACKGROUND

With the advance of display systems illumination technology fromincandescent to fluorescent to solid-state light sources, and withever-increasing miniaturization, one popular electronic category seemsnot to have kept pace. That category is large-sized personal datadisplays, such as personal computer monitors.

For many years, such monitors were based on cathode ray tube (“CRT”)technology. More recently, flat panel displays have increasinglydisplaced CRT displays. The most common form of flat panel displaysutilizes one or more fluorescent light sources located behind a liquidcrystal display (“LCD”) screen. Contemporary technology has enabled theuse of cold cathode fluorescent light (“CCFL”) light sources, butbecause a cathode emitter is still required, a high voltage source forstriking and maintaining an electric arc through the CCFL is alsorequired.

With continuing improvements in light-emitting diode (“LED”) technology,such as substantial improvements in brightness, energy efficiency, colorrange, life expectancy, durability, robustness, and continual reductionsin cost, LEDs have increasingly been of interest for superseding CCFLsin larger computer displays. Indeed, LEDs have already been widelyadopted as the preferred light source in smaller display devices, suchas those found on portable cellular telephones, personal data assistants(“PDAs”), personal music devices (such as Apple Inc.'s iPod®), and soforth.

One reason for preferring LED light sources to CCFL backlight lightsources is the substantially larger color gamma that can be provided byLED light sources. Typically, an LCD display that is illuminated by aCCFL backlight produces about 72-74 percent of the color gamma of aCRT-based NTSC display. (“NTSC” is the analog television system in usein Canada, Japan, South Korea, the Philippines, the United States, andsome other countries.) Current LED backlight display technology,however, has the potential of producing 104-118 percent or more of thatgamma color space.

Another reason for not preferring CCFL bulbs is that they containenvironmentally unfriendly mercury, which could be advantageouslyeliminated if an acceptable LED backlight light source configurationcould be developed for larger displays.

When implemented in small displays such as just described, the technicalrequirements are readily met. As is known in the art, the illuminationintensity can be rendered uniform by distributing LED light sourcesaround the periphery of the display and utilizing light diffusing layersbehind the display to equalize the display intensity. The technicalchallenges are modest because the screens are modest in size, so thatthe individual display pixels are never very far from one or more of theLED light sources. Light attenuation caused by distance from the LEDlight sources is therefore not great and is readily equalized byappropriate LED positioning coupled with suitable light diffusers behindthe display.

One way to envision the ease with which this challenge can be met insmaller displays is to consider the number of pixels, on average, thateach LED light source must support in the display, and the maximumdistances per pixel that the most distant pixels are located relative toa given LED light source. These numbers are modest (perhaps in thehundreds), so the light diminution or attenuation for the most distantpixels is similarly modest and readily compensated by suitable diffuserdesigns.

On the other hand, the larger geometries of typical flat panel computermonitors and displays (e.g., larger than about 20 inches) createarea-to-perimeter ratios that have proven untenable for current LEDtechnologies, particularly with respect to LED brightness or lightoutput. This has meant that it has proven unsatisfactory to attempt toreplace CCFL light sources with LED light sources along one or moreedges of such larger display screens. Accordingly, such displayscontinue to employ CCFL light sources even though CCFL light sources areincreasingly less desirable than LED light sources.

It would seem that a straightforward solution for replacing CCFL lightsources with LEDs would then be to arrange the LEDs in some sort ofarray configuration behind the LCD display screen, rather than aroundthe perimeter. Prior attempts to do so, however, have provenunsatisfactory. Commercially viable displays for general consumptionmust be economical to manufacture, thin, lightweight, and must provideefficient thermal management capability. Attempts to meet these criteriain acceptable form factors and costs have been unsuccessful.

Previous efforts to achieve these objectives have failed due to a numberof practical obstacles. For example, even though LED light outputs havedramatically improved in recent years, a very large number of LEDs isstill required to provide sufficient brightness in such larger displays.Typically, a minimum of several hundred LEDs must be used. This thenrequires an enormously large maze of wires and/or bulky circuit boardsto mount, support, and power such a large number of LEDs in adistributed matrix configuration. This in turn requires adequatemechanical structure to support all those components behind the LEDscreen. The resulting structure is bulky, thick, heavy, and not wellsuited for managing and removing the heat that is generated by the LEDsand the underlying electrical circuitry. It is also expensive and notwell suited for efficient manufacturing.

Another challenge with utilizing LEDs in large arrays is maintaininguniformity of color in the large numbers of LEDs. The color balance andspectra of the LEDs is limited by the phosphorescence. For example,white LEDs are often actually blue LEDs with a complementary phosphordot on the front of the LED. Depending upon manufacturing precision (andthus, related manufacturing costs), actual colors may vary from, forexample, slightly blue to slightly pink. Understandably, reducing orcompensating for such variability increases cost and complexitysignificantly as the number of LEDs increases in larger displayconfigurations and environments.

The color and the output of each LED also depend fairly sensitively ontemperature. The difficulties in providing proper thermal managementcapability can readily lead to temperature variations across thedistributed array of LED light sources. Since the color qualities of LEDlight sources are sensitively dependent upon their operatingtemperatures, such non-uniformities lead to unacceptable variations incolor from one portion of the display to another.

Additionally, it would be highly desirable to provide an LED lightsolution for large displays that is adaptable and compliant withexisting overall CCFL-based display system configurations and formfactors, so that the largest number of components (e.g., LCD screens,color diffusers, filters, housings, and so forth) can continue to beutilized without the need for major redesigns and productionmodifications.

As a result, prior efforts to replace CCFL light sources with LEDs incommercial consumer applications have largely failed to move beyond theprototype stage. The complexities, manufacturing costs, bulkiness, veryheavy weights, color non-uniformities, thermal management challenges,and so forth, have simply combined in such a way as to leave experts inthe technology convinced that they must yet await the development ofeven significantly brighter, more uniform, and less expensive LEDs.

Consumers expect and demand an excellent, consistent, and affordableconsumer experience. Prior attempts to utilize LEDs in large displayshave thus not solved the problem of building displays that are light yetrigid, thin, easy and inexpensive to manufacture, uniform in color, lowin cost, and that also provide the excellent overall high quality userexperience that customers demand and expect.

Thus, a need still remains for an improved system for a large LEDbacklight. In view of the ever-increasing commercial competitivepressures, along with growing consumer expectations and the diminishingopportunities for meaningful product differentiation in the marketplace,it is critical that answers be found for these problems. Additionally,the need to reduce costs, improve efficiencies and performance, and meetcompetitive pressures, adds an even greater urgency to the criticalnecessity for finding answers to these problems.

Solutions to these problems have been long sought but prior developmentshave not taught or suggested any solutions and, thus, solutions to theseproblems have long eluded those skilled in the art.

SUMMARY

The present invention provides a display system with a distributed LEDbacklight including: providing a plurality of tile LED light sources,each tile LED light source having a tile and a plurality of similar LEDlight sources on each tile connected for emitting light therefrom;orienting the plurality of tile LED light sources for illuminating adisplay from the back of the display; and integrating the plurality oftile LED light sources into a thermally and mechanically structurallyintegrated distributed LED tile matrix backlight light source.

Certain embodiments of the invention have other aspects in addition toor in place of those mentioned above. The aspects will become apparentto those skilled in the art from a reading of the following detaileddescription when taken with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a display system in accordance with anembodiment of the invention;

FIG. 2 is an exploded, isometric view of major components of the displaysystem of FIG. 1;

FIG. 3 is a fragmentary cross-sectional view of a display systemembodiment similar to the embodiment shown in FIG. 1;

FIG. 4 is a larger isometric view of the backlight unit shown in FIG. 2;

FIG. 5 is an enlarged fragmentary isometric view of a portion of thebacklight unit shown in FIG. 4;

FIG. 6 is a top plane view of one of the tile bars in the backlight unitshown in FIG. 4;

FIG. 7 is a side view of the tile bar shown in FIG. 6;

FIG.8A is an enlarged top view of the right end of the tile bar shown inFIG. 6;

FIG. 8B is a cross-sectional view of the tile bar shown in FIG. 6, takenalong line 8B-8B in FIG. 8A;

FIG. 9A is a side view of an embodiment of the invention showingoverlapping tiles having drop-and-slide hooks;

FIG. 9B is an isometric view of the embodiment of FIG. 9A;

FIG. 9C is an isometric fragmentary view of two rows of the overlappingtiles of FIG. 9A assembled onto an array tray;

FIG. 9D is an isometric view of another embodiment having overlappingtiles;

FIG. 9E is a side view of additional overlapping tiles connectedaccording to the embodiment of FIG. 9D;

FIG. 9F is a side view of an embodiment in which overlapping tilesoverlap by being tilted;

FIG. 9G shows a top view of an embodiment with staggered, overlappingtiles arranged to fill a regular geometric space;

FIG. 9H is a top perspective view of the several tile types shown in theembodiment of FIG. 9G;

FIG. 10A is a fragmentary isometric view of an embodiment havingsnap-together tiles that are snapped together into rows;

FIG. 10B is an inverted detail view of the snap-together system for thetiles shown in FIG. 10A;

FIG. 10C is a fragmentary isometric view of an array tray having slotstherein for receiving rows of the snap-together tiles of FIG. 10A;

FIG. 11A is an isometric view of an embodiment having tiles configuredwith side bends;

FIG. 11B is an inverted fragmentary view of tiles like those in FIG.11A, aligned for attachment to one another;

FIG. 11C is a fragmentary isometric view of an array tray receiving rowsof the assembled tiles depicted in FIG. 11A;

FIG. 12A is an end view of an embodiment having tiles attached in rowsto rails;

FIG. 12B is a fragmentary isometric view of an open frame to which therails shown in FIG. 12A are attached in overlapping fashion;

FIG. 13A is an end view of another embodiment having tiles attached inrows to rails;

FIG. 13B is a fragmentary isometric view of a portion of the embodimentof FIG. 13A;

FIG. 13C is a fragmentary isometric view of an array tray with rows ofthe embodiment of FIGS. 13A and 13B attached thereon;

FIG. 14A is an end view of an embodiment in which tiles have tile armsbent in a “U” shape around the sides of a T-rail;

FIG. 14B is a fragmentary isometric view of a portion of the embodimentof FIG. 14A;

FIG. 14C is an inverted view of the portion of the embodiment shown inFIG. 14B;

FIG. 14D is a fragmentary isometric view of rows of the embodiment shownin FIG. 14B attached to an open frame array tray;

FIG. 14E is a bottom isometric view of the corner of the structureillustrated in FIG. 14D;

FIG. 14F is a top view of an array tray with two of the FIG. 14B rowsmounted thereon;

FIG. 15A is a fragmentary isometric view of a snap-in rail embodimentthat does not require separate fasteners to attach tiles thereto;

FIG. 15B is a fragmentary isometric view of an array tray with thesnap-in rails of FIG. 15A attached thereon;

FIG. 16A is an end view of an embodiment in which tiles are held on arail by a lip;

FIG. 16B is a fragmentary isometric view of rails of the embodiment ofFIG. 16A attached to an array tray;

FIG. 17A is a fragmentary isometric view of an embodiment having adrop-and-slide configuration;

FIG. 17B is a cross-sectional side view of another embodiment havinganother drop-and-slide configuration;

FIG. 18A is an end view of an embodiment in which tiles in a rail areengaged along one edge in a retaining channel and along the oppositeedge by a spring retainer;

FIG. 18B is a fragmentary isometric view of the structure of FIG. 18A;

FIG. 18C is a view similar to that of FIG. 18B rotated clockwiseapproximately 90 degrees;

FIG. 19A is an isometric view of an embodiment in which tiles areattached directly to an array tray for additional combined structuralstrength and integrity;

FIG. 19B is an enlarged cross-sectional view of a portion of theembodiment of FIG. 19A, taken generally on line 19B-19B therein;

FIG. 20A is a top view of an embodiment in which tiles are structurallyattached to a diffuser;

FIG. 20B is a cross-sectional view of the structure of FIG. 20A taken online 20B-20B in FIG. 20A;

FIG. 21A is an isometric view of an embodiment adapted for inclusion ina sandwich type of structure;

FIG. 21B is a cross-sectional view of the structure illustrated in FIG.21A, taken on line 21B-21B in FIG. 21A, and in which the tile issandwiched between an upper plate and a lower plate;

FIG. 22A is an end view of an embodiment having an extruded tray with“T” cross bars on the top surface;

FIG. 22B is an isometric view of a portion of the embodiment of FIG. 22Awith the addition of stops on the ends thereof;

FIG. 22C is a figurative top view of an alternative configuration forholding tiles in place on the extruded tray shown in FIGS. 22A and 22B;

FIG. 23 is an end view of an embodiment in which the tiles are their ownsupporting structure, and interlock to form a structurally integratedmatrix;

FIG. 24A is an isometric view of another embodiment in which the tilesare self-supporting;

FIG. 24B is a side view of an embodiment similar to the embodiment ofFIG. 24A;

FIG. 24C is a side view of another embodiment similar to the embodimentsof FIGS. 24A and 24B;

FIG. 25A is an isometric view of an embodiment in which interlockabletiles fit together, structurally join, and interlock to form astructurally integrated, rigid, interlocked, three-dimensional tilematrix;

FIG. 25B is a fragmentary top view of a frame in which the tiles shownin FIG. 25A have been assembled in interlocked matrix form;

FIG. 25C is a partially exploded, fragmentary, isometric view of adisplay utilizing the structure of FIG. 25B, in which tiles have beenpress-fit together to form a three-dimensional structural plate and thenincorporated into a frame;

FIG. 25D is a rear isometric view of the display of FIG. 25C attached bya pivot to a support arm stand assembly;

FIG. 26 is a fragmentary side cross-sectional view of an embodiment inwhich an edge reflector provides LED edge lighting;

FIG. 27A is a fragmentary isometric exploded view of an embodiment inwhich an additional LED light bank provides LED edge lighting;

FIG. 27B is a fragmentary side cross-sectional view of the structure ofFIG. 27A assembled into a display; and

FIG. 28 is a flow chart of a display system with a distributed LEDbacklight in an embodiment of the present invention.

DETAILED DESCRIPTION

The following embodiments are described in sufficient detail to enablethose skilled in the art to make and use the invention. It is to beunderstood that other embodiments would be evident based on the presentdisclosure, and that system, process, or mechanical changes may be madewithout departing from the scope of the present invention.

In the following description, numerous specific details are given toprovide a thorough understanding of the invention. However, it will beapparent that the invention may be practiced without these specificdetails. In order to avoid obscuring the present invention, somewell-known circuits, system configurations, and process steps are notdisclosed in detail.

Similarly, the drawings showing embodiments of the system aresemi-diagrammatic and not to scale and, particularly, some of thedimensions are for the clarity of presentation and are exaggerated inthe drawing FIGs. Likewise, although the views in the drawings for easeof description generally show similar orientations, this depiction inthe FIGs. is arbitrary for the most part. Generally, the invention canbe considered, understood, and operated in any orientation.

In addition, where multiple embodiments are disclosed and describedhaving some features in common, for clarity and ease of illustration,description, and comprehension thereof, similar and like features one toanother will ordinarily be described with like reference numerals.

For expository purposes, terms, such as “above”, “below”, “bottom”,“top”, “side” (as in “sidewall”), “higher”, “lower”, “upper”, “over”,and “under”, are defined with respect to the back of the display deviceexcept where the context indicates a different sense. The term “on”means that there is direct contact among elements.

The term “system” as used herein refers to and is defined as the methodand as the apparatus of the present invention in accordance with thecontext in which the term is used.

With respect to the use of light-emitting diodes (“LEDs”) rather thancold cathode fluorescent lights (“CCFLs”), an initial concern is thermalmanagement. Normally, LEDs are mounted on a conventional printed circuitboard (“PCB”). PCB configurations are convenient, easily configurable,and economical, but they have bad thermal properties because they do notconduct heat very well, and they exhibit mismatches in coefficient ofthermal expansion (“CTE”) factors, causing reliability issues and makingthem unsuitable for large array LED configurations. Metallic substratescan provide excellent thermal performance, equalizing temperatures andconducting heat rapidly away from the LEDs. However, due to the cost,complexity, and difficulty of solving the problem of building large sucharrays and of forming circuitry thereon, conductive metallic substrateshave not been employed for large LED arrays.

One possible solution for using a PCB substrate is to bond it tightly toa thermally conductive layer, such as by attaching a thermallyconductive graphite layer to the PCB substrate with thermally conductive(e.g., copper (“Cu”)) rivets. However, when scaled up to large displays(e.g., displays larger than conventional 20-inch computer monitors), thesize and complexity of those displays (containing, for example, over1000 LEDs) become unwieldy and uneconomical.

As explained herein, the present invention solves these problems byproviding a display system that combines and utilizes a number of tileLED light sources. As used herein, the terms “tile” and “tile LED lightsource” are defined, according to the context in which used, to mean anassembly, formed integrally on a thermally conductive substrate, with atleast two similar or substantially matching LED light sources physicallymounted and electrically connected thereon and configured for emittinglight therefrom, and with fewer than the total number of LED lightsources utilized by the display system into which the tile isincorporated. When used with the term “tile”, the term “thermallyconductive” is defined to mean having thermal conduction propertiescomparable to or better than those of metal.

In one embodiment, each tile is formed of a metallic substrate witheight similar or matching LED light sources thereon, each LED lightsource emitting visible white light. Various display system backlightconfigurations are then described having a variety of optimizations forattaining co-planarity of the tiles, uniform heat management, weightminimization, efficient manufacturability, economical serviceability,stiffness in various directions, performance efficiency, reduced numberof components, efficient assembly operations, optimized assemblygeometries, reduced complexity, torsional rigidity, reduced thickness,optimized thermal mechanical outcomes, efficiencies in functionaldependencies, creation and maximization of heat exchange surface areafor higher massflow and lower velocity air convection (either natural orforced), and so forth, according to the sizes and applicationenvironments in which particular such configurations and solutions maybe employed.

Referring now to FIG. 1, therein is shown a perspective view of adisplay system 100 having a display assembly 102 supported in a frame104. In turn, the frame 104 is supported on a stand 106. The displaysystem 100 has a distributed LED backlight (not shown, but see thebacklight unit 220 in FIG. 2). As used herein, the term “backlight” isdefined to mean a form of illumination that provides light for a displaythat illuminates the display from the back of the display. Thisdefinition means that the light is presented to the side of the displayopposite the side of the display that is viewed, such that the light isshining through the display toward the viewer rather than reflectingtoward the viewer from the front side of the display. As used herein,the term “distributed” is defined to mean that the LED light sources ofthe LED backlight are positioned across and within the display area ofthe display assembly 102, and not just around the periphery thereofadjacent the front bezel (e.g., the front bezel 202 in FIG. 2).

Referring now to FIG. 2, therein is shown an exploded, isometric view ofthe majority of the major components of the display assembly 102. Theframe 104 (FIG. 1) includes a front bezel 202, a panel frame 204, andpanel side rails 206.

The display assembly 102 also includes a liquid crystal display (“LCD”)sub-assembly 208 that connects to LCD circuitry 210. In one embodiment,the LCD sub-assembly 208 utilizes thin film transistor (“TFT”)technology to form a TFT LCD display, as is known in the art.

Beneath the LCD sub-assembly 208 are backlight diffuser sheets 212,beneath which is a reflector 214 having holes 216 therein that receiveLEDs 218 on a backlight unit 220. The reflector 214 is thus positionedaround the LEDs 218. The LEDs 218 are oriented forwardly toward the LCDsub-assembly 208 for illuminating the display assembly 102 from the backof the display.

The backlight unit 220 is physically and thermally attached to an arraytray 222. A heat spreader 224, such as a graphite sheet, is attached tothe back of the array tray 222 opposite the backlight unit 220 toconduct heat rapidly away therefrom and to equalize temperaturesthroughout the backlight unit 220. By connecting directly to the arraytray 222 to which the backlight unit 220 is physically and thermallyattached, the heat spreader 224 thermally integrates therewith,including with the tiles (see the tiles 404 in FIG. 4) in the backlightunit 220.

Beneath the heat spreader 224 are two LED driver circuit boards 226, oneon either side of the display assembly 102. Beneath one of the LEDdriver circuit boards 226, toward one side of the display assembly 102,is an LCD controller power control board 228 that is protected by an LCDcontroller shield 230 therebeneath. An LED power supply 232 is attachedbeneath the other LED driver circuit board 226 on the other side of thedisplay assembly 102, opposite the LCD controller power control board228. An LED power supply insulator 234 protects the LED power supply232.

Referring now to FIG. 3, therein is shown a fragmentary cross-sectionalview of an embodiment of a display system 100′ similar to the displaysystem 100 (FIG. 1). To aid in producing uniform illumination of the LCDsub-assembly 208, the backlight unit 220 is spaced from the LCDsub-assembly 208 by spacers 302.

Referring now to FIG. 4, therein is shown a larger isometric view of thebacklight unit 220. The backlight unit 220 is formed of a series of tilebars 402 arranged adjacent and parallel to each other. Each tile bar 402is formed of a number of tiles 404 attached in a series on top of a tilebar rail 406.

Referring now to FIG. 5, therein is shown an enlarged fragmentaryisometric view of a portion of the backlight unit 220 assembled onto thearray tray 222 and attached thereto by screws 502. The tile bars 402 arearranged in alternating positions (as also shown in FIG. 4), with oneend of each tile bar 402 being provided with an electrical connector504.

The electrical connectors 504 are connected directly to the tiles 404thereadjacent. Electrical power for the remaining tiles 404, in arespective tile bar 402, is provided by wire bonds 506 that electricallyconnect adjacent tiles by jumping from tile to tile along the respectivetile bars 402 to connect through-conductors (not shown) that are formedin each tile 404.

The tiles 404 themselves are individual structures that physically andelectrically support and interconnect the LEDs 218 the same surface ofthe tile 404. Further, as indicated, in one embodiment, as shown, thetiles 404 also provide electrical continuity for connecting to andproviding power to adjacent tiles, such as by means of the wire bonds506.

Also, the LEDs 218, which in one embodiment, as illustrated, areprovided eight per tile 404, are actually LED clusters in variousembodiments. In such clusters, each of the LEDs 218 is actually acluster of four discreet LEDs, one blue LED, one red LED, and two greenLEDs. Each such cluster is encapsulated, for example, with silicone, andthe individual discrete LEDs therein are then electrically driven toemit respective intensities that combine to provide white light fromeach such LED 218 cluster.

In other embodiments, other LED configurations may be utilized. Forexample, white only LEDs may be employed.

To provide for excellent thermal conductivity and performance, the tiles404 are formed of aluminum (“Al”) substrates on which there is a thinthermally conductive but electrically insulating layer. On the top ofthis electrically insulating layer, the LEDs and associated circuitryare formed, for example, by conventional semiconductor fabricationprocesses. This beneficially provides for excellent thermal performance,and enhances heat conduction into the support structures to which thetiles 404 are attached, such as the tile bars 402, and so forth. As usedherein, therefore, the term “thermally structurally integrated” isdefined to mean that the tiles are thermally conductive (not insulating)and actively contribute to their own heat removal in cooperation andcombination with the physical support structure to which they areattached, such that the combination of the tiles and such supportstructure attains heat flow thereamong that is greater than would beattained using a tile having a substrate formed of a material having alower heat conductivity than metal.

Additionally, by forming the tiles 404 in this manner with a metallicsubstrate, not only is excellent thermal performance achieved, but thetiles also have superior formability and machineability such that thetiles can be shaped, if desired, into complex configurations, asillustrated further herein.

Importantly, the tiles 404 are strong enough to become active structuralelements, i.e., mechanical building blocks, that can be mechanicallystructurally integrated into integrated LED tile matrices rather thansimply riding passively on an external supporting structure. That is, byintegrating into and becoming part of their own structural supportmatrix, external support requirements can be substantially reduced,resulting in significant savings in weight, cost, display thickness, andso forth. As used herein, therefore, the term “mechanically structurallyintegrated” is defined to mean that the tiles actively contribute totheir own physical support, and when attached to an additional physicalsupport structure, that the tiles function in cooperation andcombination therewith such that the combination of the tiles and suchsupport structure is stronger and more rigid than the support structurealone. As used herein, the term “passively” is accordingly defined tomean: attaching tiles in a manner such that structural assistance andphysical support is not effectively provided by the tiles.

According to the present invention and the particular embodiments underconsideration, the tiles may be joined to one another in aself-supporting mechanically structurally integrated structure.Alternatively, the tiles may be mechanically structurally integratedwith an additional support structure such that the additional supportstructure may be lighter in weight, thickness, and so forth, and lessrobust than would be necessary to support itself and the tiles were thetiles riding passively and not assisting in the structural supportthereof. In other words, because of the mechanical structuralintegration with the tiles, such an additional support structure may bedesigned so that it is not strong enough to support itself andself-maintain its profile when burdened passively with the weight of anumber of tile LED light sources. This is possible because the tile LEDlight sources are then actively combined and structurally integratedwith and assist the additional support structure to help in providingsupport as well, so that together the integrated structure hassufficient strength and integrity to support the total combined weight.

It will be further understood based upon this disclosure that the tiles,as a result of their configurations, and where disclosed, theircombinations with additional support structure, according to theparticular embodiments, are integrated into three-dimensionallymechanically structurally integrated backlight light sources. This meansthat the integrated backlight light source structures provide enhancedstrength, integrity, and rigidity in all three dimensions, and not justin a two dimensional planar sense.

Referring now to FIG. 6, therein is shown a top plane view of a tile bar402.

Referring now to FIG. 7, therein is shown a side view of the tile bar402 shown in FIG. 6.

Referring now to FIG. 8A, therein is shown an enlarged top view of theright end of the tile bar 402 shown in FIG. 6.

Referring now to FIG. 8B, therein is shown a cross-sectional view of thetile bar 402 taken on line 8B-8B in FIG. 8A. A thermally conductiveadhesive 802 adheres the tile 404 structurally to the tile bar rail 406of the tile bar 402 such that the combined tile 404 and tile bar rail406 are united into a unit that is stronger and more rigid than eitherthe tile 404 or the tile bar rail 406 alone.

Referring now to FIG. 9A, therein is shown a side view of an embodiment900 of overlapping tiles 902 provided with drop-and-slide hooks 904.Adjacent overlapping tiles 902 may be attached to each other by screws906, or by other appropriate attachments selected, for example, fromrivets, clinch rivets, spot welds, line welds, screws, and a combinationthereof.

To preserve co-planarity of the overlapping tiles 902, a drop jog 908 isprovided on one end of each of the overlapping tiles 902. The drop jog908 forms a jogged end 910 at the tile end, dropped sufficiently to slipunderneath the tile next adjacent thereto while keeping the overlappingtiles 902 themselves flat and co-planar.

Referring now to FIG. 9B, therein is shown an isometric view of theembodiment 900. In this embodiment, alignment holes 912 are providedthrough each end of the overlapping tiles 902. The alignment holes 912provide a convenient mechanism for aligning the overlapping tiles 902for assembly into rows, as illustrated. Such assembly can be easilyaccomplished, for example, by locating the alignment holes 912 ontopre-positioned pins (not shown) to hold the overlapping tiles 902 inposition while the screws 906 are tightened. By this means, the tilescan be quickly and accurately aligned for assembly to each other.

It will also be readily understood by one of ordinary skill in the art,based upon the teachings in the present disclosure, that other suitablefasteners and/or attachments may be employed, as desired or appropriate,in place of the screws 906. Such attachments would include, for example,rivets, clinch rivets, spot welds, line welds, and the like, and may beutilized as appropriate with any of the tile configurations disclosedherein.

Referring now to FIG. 9C, therein is shown an isometric fragmentary viewof an assembly 914 in which two rows 916 of the overlapping tiles 902have been assembled onto an array tray 918. It will be understood, ofcourse, that in a finished display, the array tray 918 would have manymore rows 916 assembled thereonto. Only two rows 916 are illustrated inorder to better reveal details of the assembly 914, including the arraytray 918 that is beneath the rows 916.

Similarly, in other embodiments disclosed and illustrated herein, only afew tile rows will generally be shown so that the details of the arraytrays to which they are attached, in several of the embodiments, can bebetter shown.

The array tray 918 is provided with slots 920 that are located toreceive the drop-and-slide hooks 904 of the overlapping tiles 902. Theassembly 914 is then easily and quickly assembled by dropping thedrop-and-slide hooks 904 through the slots 920 and sliding the rows 916to cause the drop-and-slide hooks 904 to engage underneath the ends ofthe slots 920, thereby attaching the overlapping tiles 902 to the arraytray 918.

To increase the strength, integrity, and rigidity of the array tray 918,one or more stiffeners 922 may be provided, for example, on theunderside of the array tray 918 opposite the rows 916 that are on thetop of the array tray 918. This further assists in maintaining theflatness of the array of the tiles 902.

Referring now to FIG. 9D, therein is shown an isometric view of anembodiment 924 having overlapping tiles 926. In the embodiment 924, eachof the overlapping tiles 926 has a jog 928 located intermediatelythereon that forms a foot 930 that, by comparison, is proportionatelysignificantly larger than the jogged ends 910 (FIG. 9A) of embodiment900 (FIG. 9A). Also, rather than being arranged in rows, such as therows 916 (FIG. 9C), the overlapping tiles 926 are staggered bothlongitudinally and laterally, and are connected to each other byfasteners 932.

The staggered configuration of the overlapping tiles 926 and the largersizes of the feet 930 provide sufficient structural and physicalstrength and integrity for the overlapping tiles 926 to beself-supporting without the need for an underlying array tray. Thesignificant overlap and staggered configuration also significantlyimprove thermal conduction between and among the overlapping tiles 926,aiding temperature uniformity and heat removal for superior performance.

Referring now to FIG. 9E, therein is shown a side view of additionaloverlapping tiles 926 connected according to the embodiment 924 of FIG.9D.

Referring now to FIG. 9F, therein is shown a side view of an embodiment934 in which overlapping tiles 936 overlap by being tilted. When theoverlapping tiles 936 overlap by tilt, as illustrated, it is possiblethat the LEDs 218 may not emit light in the desired direction, since thelight may tend to emit perpendicularly to the surfaces of the individualoverlapping tiles 936. In that case, it may be desirable to fabricatethe LEDs 218 so that they emit more in the desired direction, such as atan appropriate angle to the top surfaces of the overlapping tiles 936.

With respect to the embodiment 934, the tilted and overlapping tiles 936form a configuration, for example, somewhat like roof tiles, and thusaverage out overall to a flat surface. This illustrates that, dependingupon the configuration, the overlapping tiles 936 do not necessarilyneed to be orthogonal with respect to the environment, nor do the LEDs218 need to be orthogonal. In such a case, when tilted in this fashionrather than planar, the LEDs 218 can then be fabricated, as indicated,to direct the light as desired. That is, the LEDs 218 can be grown at acompensating angle, for example. Such an overlapping or tiledarrangement has several advantages, for example, providing improvedstructural strength, integrity, and rigidity, and improved heat transferand heat management characteristics.

Referring now to FIGS. 9G and 9H, therein is shown an embodiment 938illustrating, for example, how staggered tiles, such as the overlappingtiles 926 in FIG. 9D, can be arranged to fill a regular geometric space,such as a rectangle, having straight edges. In this embodiment, themajority of the tiles are overlapping tiles 940, for example similar tothe overlapping tiles 926, arranged in a herringbone pattern. Then, toaccommodate the staggered configuration, half tiles 942 are provided onthe ends of alternating rows. The half tiles 942 are substantially thesame as the overlapping tiles 940 but only approximately half as wide.Finally, to accommodate each foot 944 of the overlapping tiles 940 and942 along the top edge perimeter 946, cap tiles 948 are provided forpositioning over the feet 944. In one embodiment, the cap tiles 948 aresubstantially the same as the overlapping tiles 940 except that the captiles 948 do not have feet 944. The embodiment 938 thus provides theadvantages of a staggered overlap to enhance thermal conduction andmechanical connection of the tiles in all directions, while also fittingsnugly into a space that has straight edges.

Referring now to FIG. 10A, therein is shown a fragmentary isometric viewof an embodiment 1000 in which snap-together tiles 1002 are snappedtogether into rows. In this embodiment, the snaps that hold thesnap-together tiles 1002 together are flexures 1004, at one end of eachsnap-together tile 1002, that are springably received in matching slots1006 at the opposite ends of the snap-together tiles 1002. Inparticular, each flexure 1004 has a detent 1008 on the end thereof thatis springably received in its matching slot 1006 on the adjacentsnap-together tile 1002.

Electrical connections and electrical continuity may be provided betweenthe snap-together tiles 1002 by any suitable means, such as anelectrically conductive tape 1010, edge connectors (not shown) flexinterconnects (not shown), the optional use of pad connectors (notshown), and so forth.

Advantageously, it will now be understood by those of skill in the art,based upon the teachings herein, that electrical connections between andamong the tiles of the various other embodiments disclosed herein maylikewise be readily achieved and provided by conductive tape, edgeconnectors, and so forth, as disclosed herein and as desired andappropriate for the particular configurations and embodiments at hand.

Referring now to FIG. 10B, therein is shown an inverted detail view ofthe flexure 1004 and slot 1006 snap-together system for thesnap-together tiles 1002.

Referring now to FIG. 10C, therein is shown a fragmentary isometric viewof an array tray 1012 having slots 1014 therein for receiving rows 1016of the snap-together tiles 1002. The rows 1016 of the snap-togethertiles 1002 can be secured to the array tray 1012, for example, by screws1018 that pass through the snap-together tiles 1002 to engage in screwholes 1020 in the array tray 1012.

Referring now to FIG. 11A, therein is shown an isometric view of anembodiment 1100 having tiles 1102 that are configured as side bendtiles. In this embodiment, the tiles 1102 have side bends 1104 along,for example, the longitudinal sides thereof, extending downwardly fromthe major top surfaces of the tiles 1102, and providing increasedrigidity for the tiles 1102.

Each side bend 1104 has a tab 1106 at one end. Holes 1108 are formed ateach end of the side bends 1104. The side bends 1104 in this embodimentare split and slightly staggered inwardly and outwardly, from one end tothe other, so that they can overlap when the tiles 1102 are assembled toeach other in series.

When the tiles 1102 are assembled in series into rows, the holes 1108 inthe side bends 1104 line up so that the tiles 1102 can be secured toeach other by screws 1110. This results in a strong row of assembledtiles 1102 having increased rigidity. With this configuration, the tiles1102 can also be self-aligning.

Referring now to FIG. 11B, therein is shown an inverted fragment oftiles like the tiles 1102 shown in FIG. 11A, aligned for serialattachment to one another and showing in greater detail the alignment ofthe holes 1108.

Referring now to FIG. 11C, therein is shown a fragmentary isometric viewof an array tray 1112 receiving rows 1114 of the assembled tiles 1102.The array tray 1112 has an extruded corrugated configuration thatprovides additional strength, integrity, and rigidity. Depending uponthe particular dimensions that are provided, the array tray 1112 canalso provide self-alignment for the tiles 1102. The rows 1114 of thetiles 1102 may be secured to the array tray 1112 by any suitable means,such as screws 1116 passing through the tiles 1102 into holes 1118 inthe array tray 1112.

Referring now to FIG. 12A, therein is shown an end view of an embodiment1200 having tiles 1202 that are not attached directly to one another,but instead are attached in groups to rails 1204. (A single tile 1202and single rail 1204 are shown in FIG. 12A.) The rails 1204 thenassemble and support the groups of the tiles 1202 into row structuresformed thus with increased rigidity. In one embodiment, the rails 1204are sheet metal rails having a jog 1206 allowing the rails 1204 to beassembled to each other in overlapping fashion (see FIG. 12B).

For ease and simplicity of assembly, the rails 1204 have a return 1208along one side that forms a pocket 1210. The tiles 1202 are thencaptured along one tile edge in the pocket 1210, and then securelyattached to the rail 1204 with only a single tile screw 1212. That is,the return 1208 creates a “V” shape that forms the pocket 1210 thateasily captures a tile therein, providing for rapid and secure assemblywith the requirement of only the single tile screw 1212.

Referring now to FIG. 12B, therein is shown a fragmentary isometric viewof an open frame 1214 to which the overlapping rails 1204 are attachedwith rail screws 1216. Unlike the array trays in previous embodiments ofthe present invention, the overlapping sheet metal rails 1204 providesufficient increased rigidity that an entire tray is not required.Instead, weight and material savings can be realized by using an openframe such as the open frame 1214.

Referring now to FIG. 13A, therein is shown an end view of an embodiment1300 also having tiles attached in rows to rails. In embodiment 1300,tiles 1302 are mounted longitudinally in a row (see FIG. 13B) on a rail1304. The rail 1304 may be extruded, and has a pocket 1306 formed alongone side by a return 1308 to capture an edge of the tile 1302 therein.The bottom of the pocket 1306 includes a small radius clearance 1310that is undercut slightly below the surface of the rail 1304 on whichthe tile 1302 is mounted.

The small radius clearance 1310, thus located under the edge of the tile1302 that is captured in the pocket 1306, provides a thickness tolerancefor the tiles 1302, particularly where the pocket 1306 is dimensionedclose to the thickness of the tiles 1302. In this way, slight variationsin tile thicknesses are accommodated by the small radius clearance 1310beneath the pocket 1306, allowing thicker tiles to fit and bend slightlyinto the small radius clearance 1310.

Opposite the pocket 1306, on the other side of the rail 1304, is a hole1312 in the rail 1304. The hole 1312 aligns with a matching hole 1314 inthe tile 1302, so that a clip 1316, such as a U-shaped spring steelclip, formed with protrusions 1318, can capture and retain the tiles1302 on the rails 1304 by clipping the protrusions 1318 into the holes1312 and 1314. Consequently, the small radius clearance 1310 effectivelyprovides for preloading the tile edge therein to provide a thicknesstolerance for the tiles 1302. The clips 1316 provide for rapid and easyassembly of the tiles 1302 onto the rails 1304, typically faster thanwould be required to align and assemble with screws. This also resultsin the formation of rows with increased rigidity.

Referring now to FIG. 13B, therein is shown a fragmentary isometric viewof a portion of the embodiment 1300.

Referring now to FIG. 13C, therein is shown a fragmentary isometric viewof an array tray 1320 on which rows 1322 of the embodiment 1300 areattached. Holes 1324 provide clip clearance for the clips 1316 in thearray tray 1320. The array tray 1320 provides additional stiffness forthe embodiment 1300, particularly in the direction transverse thereto.This further assists in maintaining the flatness of the array of thetiles 1302.

Referring now to FIG. 14A, therein is shown an end view of an embodiment1400 in which tiles 1402 have tile arms 1404 along the sides thereofthat are bent in a “U” shape around the sides of a T-rail 1406 to engagethe T-rail 1406 and attach themselves thereto. Each T-rail 1406 thenserves as a substrate that defines a row of the tiles 1402, which areaffixed in a longitudinal series thereon, forming rows with increasedrigidity.

Referring now to FIG. 14B, therein is shown a fragmentary isometric viewof a portion of the embodiment 1400.

Referring now to FIG. 14C, therein is shown an inverted view of theportion of the embodiment 1400 shown in FIG. 14B. Tips 1408 of springfingers 1410, extending longitudinally from the tile arms 1404 on theunderside of the T-rail 1406, are received and held in correspondingpockets 1412 in the T-rail 1406 to secure the tiles 1402 in position onthe T-rail 1406.

The embodiment 1400 thus provides increased rigidity due to theincreased strength and integrity provided by the T-rails 1406 and thestructural stiffening afforded by the bent-around tile arms 1404. Thisfurther assists in maintaining the flatness of the array of the tiles1402. The T-rails 1406 may be economically and efficiently fabricated,for example as extrusions, and the pockets 1412 may then be formedtherein by any suitable conventional process.

Concerning the spring fingers 1410, they not only conveniently locatethe respective tiles 1402 in the proper locations on the T-rails 1406,but the spring fingers 1410 additionally pressure the tiles 1402 forwardand against the T-rails 1406 for improving convective area and heatexchange thermal contact therebetween.

Referring now to FIG. 14D, therein is shown a fragmentary isometric viewof rows 1414 of the embodiment 1400 attached to an array tray 1416 byscrews 1418. The array tray 1416, for this embodiment 1400, is an openframe having cut outs 1420 therein that define cross members 1422. Thecut outs 1420 advantageously reduce the weight of the array tray 1416.While the cut outs 1420 also reduce the overall strength of the arraytray 1416, this is acceptable due to the additional stiffness, strength,integrity, and rigidity provided by the companion T-rails 1406 with thetiles 1402 attached thereon.

Referring now to FIG. 14E, therein is shown a bottom isometric view ofthe corner of the structure illustrated in FIG. 14D. The inner edge ofthe array tray 1416 along the cut outs 1420 is bent over and under thearray tray 1416 to form a hem 1424. The configuration of the hem 1424 isa stiffness-improving feature for the array tray 1416. This furtherassists in maintaining the flatness of the array of the tiles 1402.

Referring now to FIG. 14F, therein is shown a top view of the array tray1416 with two of the rows 1414 mounted thereon.

Referring now to FIG. 15A, therein is shown a fragmentary isometric viewof an embodiment 1500 in which no fasteners are separately required toattach tiles 1502 to a snap-in rail 1504. Instead, the snap-in rails1504 in the embodiment 1500 have hooks 1506 placed at intervalstherealong slightly longer than the lengths of the tiles 1502. Thesnap-in rails 1504 may, for example, be constructed of sheet metal, andthe hooks 1506 may be punched up therefrom and formed so that the tiles1502 can be slipped under the hooks 1506 and captured therein to formrows with increased rigidity.

Assembly of the tiles 1502 onto the snap-in rails 1504 is thencompleted, after hooking the tiles 1502 under the hooks 1506, byrotating the tiles 1502 downwardly past snap-in retainers 1508 onto thesnap-in rail 1504. The snap-in retainers 1508 are flexures having abeveled detent 1510 thereon just above the upper surface of the snap-inrail 1504 and positioned to project slightly over a tile 1502 whensnapped into position and retained at the opposite end by the hook 1506.The snap-in retainers 1508 may be formed from the material of thesnap-in rails 1504, or may be inserted as a separate spring part, asdesired.

Each tile 1502 is then snapped into position by pressing the endadjacent the snap-in retainers 1508 downwardly causing the detent 1510to flex momentarily out of the way and then snap back over the tile 1502to capture it in place.

When the tiles 1502 are thus snapped onto the snap-in rail 1504, eachtile is held in position by a hook 1506 and a snap-in retainer 1508. Thehook 1506 receives and holds one end of the tile 1502, and the snap-inretainer 1508 forms a spring-snap flexure that receives and holds theopposite end of the tile 1502.

The snap-in rail 1504 may advantageously have sheet metal bends 1512formed longitudinally along the longitudinal edges thereof to addlongitudinal stiffness to the snap-in rails 1504. Consequently, thesnap-in rails 1504 form rows with increased rigidity, part of theincreased rigidity resulting from the combination of the stiffness fromthe tiles 1502 being attached to the snap-in rails 1504, and part of theincreased rigidity being a result of the sheet metal bends 1512 that areformed along the longitudinal edges of the snap-in rails 1504. Thisfurther assists in maintaining the flatness of the array of the tiles1502.

Referring now to FIG. 15B, therein is shown a fragmentary isometric viewof an array tray 1514 onto which snap-in rails 1504 are attached, forexample, by screws 1516.

Referring now to FIG. 16A, therein is shown an end view of an embodiment1600 in which tiles 1602 are held securely on a rail 1604 by a lip 1606,forming rows with increased rigidity. The lips 1606 are formedintegrally on the rails 1604, for example by extrusion of the rails1604. Initially in an open position, the lip 1606 is then deformed, forexample under the force of a press (not shown), to bend the lip 1606,such as in the direction of the arrow 1608, over and onto the tiles 1602along one longitudinal edge thereof In this manner, the tiles 1602 arecaptured and held tightly on the top of the rails 1604 by the lip 1606.That is, the lips 1606 are deformable onto the edges of the tiles 1602thereadjacent, retaining the tiles 1602 underneath the lip 1606 bydeforming the lip 1606 thereagainst.

Referring now to FIG. 16B, therein is shown a fragmentary isometric viewof several rails 1604 of the embodiment 1600 positioned on an array tray1610. Each of the rails 1604 may be attached to the array tray 1610 byscrews (not shown) inserted through screw holes 1612 in the rails 1604.

Retention of the tiles 1602 by the lip 1606 may be enhanced by holes1614 formed in the edges of the tiles 1602 in positions that locate theholes 1614 underneath the lip 1606 after it is deformed or bentthereover. The lips 1606 then engage the holes 1614 therebeneath,thereby enhancing retention of the tiles 1602. In other words, when thelip 1606 is crimped onto the tile 1602, a little bit of the materialfrom the lip 1606 actually extrudes into the holes 1614, therebycatching the tile 1602. Consequently, the tile 1602 can be firmlyattached to the rail 1604 without requiring any separate fasteners.

Referring now to FIG. 17A, therein is shown a fragmentary isometric viewan embodiment 1700 having a drop-and-slide configuration in which tiles1702 have slots 1704 therein that match hooks 1706 on a rail 1708. Thehooks 1706 are drop-and-slide hooks such that the tiles 1702 are droppedover the hooks 1706 and receive the hooks 1706 through the slots 1704.The tiles 1702 are then slid horizontally to slip underneath the hooks1706 to be engaged and held firmly against the rail 1708. Upon slidinginto position, a spring finger 1710 is then revealed and releasedagainst the end of the tile 1702 that moves toward the hooks 1706 as thetiles 1702 is being slid thereunder. The spring finger 1710 then holdsthe tiles engaged with the hooks 1706 to lock the tiles 1702 on the rail1708 to form rows with increased rigidity. The tiles 1702 can thus beattached to the rails 1708 without separate fasteners.

The combination of the tiles 1702 captured in this fashion on the rail1708 forms a row with increased rigidity.

Similarly, the rails 1708 can be attached to an array tray 1712 withoutseparate fasteners by engaging tabs 1714 formed on and underneath therails 1708 into clips 1716 on the array tray 1712. In one embodiment, asshown, the tabs 1714 and the clips 1716 are configured to constitute adrop-and-slide feature, such that the tabs 1714 drop beneath the clips1716, below the array tray 1712, so that the rail 1708 is held snuglyagainst the array tray 1712.

For providing electrical continuity between the tiles 1702, a ribbonconnector 1718 is provided between adjacent tiles 1702.

Referring now to FIG. 17B, therein is shown a cross-sectional side viewof an embodiment 1720 having another drop-and-slide configuration. Inthis embodiment, a rail 1722 is attached to an array tray 1724, and therail 1722 has an end stop 1726 mounted thereon to hold the tiles 1702engaged with the hooks 1706 to lock the tiles 1702 on the rails 1722.

The embodiment 1720 illustrates additional aspects of the presentinvention, wherein the versatility of the invention, for example, allowsthe array tray 1724 to function as well as the external housing for thedisplay, or vice versa. Also shown is a PCB 1728 captured and supportedin a stand 1730 beneath the tiles 1702. Additionally, the hooks 1706 maybe configured to provide electrical connections (not shown) to the tiles1702.

Referring now to FIG. 18A, therein is shown an end view of an embodiment1800 in which tiles 1802 are engaged along one edge in a retainingchannel 1804 of a rail 1806 on which the tiles 1802 are placed. Therails 1806 may be formed, for example, by extrusion. In one embodiment,the retaining channels 1804 are shaped as overhanging lips formed alongone edge of the rail 1806 and extending upwardly and over the topsurface of the rail 1806 and over the adjacent edge of each of the tiles1802 when located thereon.

Once the tiles 1802 are in position on the top of the rail 1806 andcaptured along one edge in the retaining channel 1804, a retainer spring1808 is then positioned downwardly against the edges of the tiles 1802along the edge of the rail 1806 opposite the retaining channel 1804. Theretainer spring 1808 is then secured in position, for example, by screws1810.

The retainer springs 1808 may be formed of a suitable resilientmaterial, such as spring steel, and function thereby not only to holdthe tiles 1802 in place on top of the rails 1806, but to maintain adownward and lateral pressure on the tiles 1802. The retainer springs1808 thus press the tiles 1802 against the rails 1806 for better heattransfer, hold the tiles 1802 in position on the rails 1806 againstvibration, and so forth. The retainer springs 1808 also press the tiles1802 laterally toward the retaining channel 1804 for better attachmentto the rails 1806.

Referring now to FIG. 18B, therein is shown a fragmentary isometric viewof the structure in FIG. 18A. In one embodiment, the retainer springs1808 have a relief 1812, or slot, fox med between each of the tiles1802. The reliefs 1812 provide retainer springs 1808 that are at leastpartially discontinuous between the tiles 1802, thereby largelyseparating the portions of the retainer springs 1808 that contact eachof the tiles 1802. Consequently, each tile effectively has its ownretainer spring 1808, since the spring sections are individualized andseparated from each other by the reliefs 1812.

Referring now to FIG. 18C, therein is shown a view similar to that shownin FIG. 18B but rotated clockwise approximately 90 degrees to bettershow access gaps 1816 that may be formed in one or more corners of thetiles 1802. The access gap 1816 is akin to a missing corner and, whenadjacent the retainer spring 1808, provides ready access to the tile1802 for engaging the tile to pry the tile loose from underneath theretainer spring 1808. This facilitates removing the tile without havingto remove the entire retainer spring 1808. The reliefs 1812 furtherfacilitate such individual tile removal.

The combination of the tiles 1802 attached securely to the rails 1806thus forms rows of the tiles 1802 with increased overall rigidity. Screwholes 1814 in the rails 1806 provide a convenient configuration andmeans for attaching the rails 1806 to an underlying support structure,such as an array tray (not shown).

Advantageously, the embodiment 1800 thus provides for readily, quickly,and efficiently assembling tiles 1802 into rows with a minimum number offasteners while securely holding the tiles 1802 in position.

Referring now to FIG. 19A, therein is shown an isometric view of anembodiment 1900 in which tiles 1902 are attached directly to an arraytray 1904 to give the array tray 1904 sufficient additional combinedstructural strength and integrity to enable the array tray 1904 tosupport the tiles 1902 that are attached directly thereon. As usedherein, the phrase “to enable it to support” is defined to mean that thearray tray 1904 is not strong enough to support the tiles 1902 on itsown, and can support the tiles 1902 only by virtue of the additionalstructural strength and integrity provided by the tiles 1902 themselves,and working in concert with the array tray 1904.

The array tray 1904 may be formed, for example, by forming sheet metal.The sides of the array tray 1904 may include legs 1906 that extend at anangle therefrom to further stiffen and strengthen the array tray 1904and tile 1902 assembly. This further assists in maintaining the flatnessof the array of the tiles 1902.

The legs 1906 may additionally be formed, for example, to reach aroundand define a PCB area 1908 in which PCBs such as PCBs 1910, and otherelectrical/electronic components, may be attached and supported.

These components can then all be thermally as well as structurallyintegrated, such as, for example, by using a thermal grease or otherthermally conducting material (not shown) between the tiles 1902 and thearray tray 1904, and similarly providing heat conducting facilitiesbetween the PCBs 1910 and the array tray 1904. Effective heat conductionaway therefrom by the array tray 1904 can be facilitated, for example,by forming feet 1912 on the bottom of the legs 1906 of the array tray1904. The feet 1912 can then be attached to a suitable frame or bodymember for removing heat therefrom, as well as supporting the array tray1904 and assembled components within a display.

Referring now to FIG. 19B, therein is shown an enlarged cross-sectionalview of a portion of the embodiment 1900 illustrated in FIG. 19A, takengenerally on line 19B-19B in FIG. 19A. In this embodiment, the tiles1902 can be conveniently and efficiently attached to the array tray 1904by suitable fasteners, such as pairs of rivet fasteners 1914. In oneembodiment, a clinch rivet metal fastener can be used, such as a TOX®fastener (“TOX” is a registered trademark of PRESSOTECHNIK GMBHCorporation, Weingarten, Germany).

Referring now to FIG. 20A, therein is shown a top view of an embodiment2000 in which tiles 2002 are structurally attached to the underside of aclear or translucent diffuser, such as a diffuser plate 2004. The tilescan be attached to the diffuser plate 2004 by any suitable means, suchas a screw fastener 2006, thereby reinforcing the diffuser plate 2004 togive it sufficient additional structural strength and integrity toenable it to support the tiles 2002 attached thereon.

Referring now to FIG. 20B, therein is shown a cross-sectional view ofthe structure of FIG. 20A taken on line 20B-20B in FIG. 20A.

Referring now to FIG. 21A, therein is shown an isometric view of anembodiment 2100 in which a tile 2102 has a screw hole 2104 therethrough,passing from top to bottom, and a notch 2106 in at least one of thesides. The tile 2102 is thereby well adapted for inclusion in a sandwichtype of structure.

Referring now to FIG. 21B, therein is shown a cross-sectional view ofthe structure illustrated in FIG. 21A, taken on line 21B-21B therein,and in which the tile 2102 is sandwiched between an upper plate 2108 anda lower plate 2110. A screw 2112 passes through a screw hole 2114 in theupper plate 2108. The screw hole 2114 is aligned with the screw hole2104 in the tile 2102, so that the screw 2112 can pass through the screwholes 2104 and 2114 to engage a nut 2116 that is anchored in the lowerplate 2110. This configuration structurally attaches the tile 2102between the upper plate 2108 and the lower plate 2110 to give the upperplate 2108 and the lower plate 2110 sufficient additional structuralstrength and integrity to enable them to support the tiles 2102 attachedthereon and therebetween.

To align the tiles 2102 on the lower plate 2110, a half shear 2118 maybe provided on the upper surface of the lower plate 2110 to engage thenotches 2106 in the tile 2102. This provides for rapid and accurateassembly, and permits the use of but a single screw 2112 to assembleeach tile 2102 accurately and to hold the assembly together.

Referring now to FIG. 22A, therein is shown an end view of an embodiment2200 in which an extruded tray 2202 has “T” cross bars 2204 formed onand extending over the top surface thereof. The “T” cross bars 2204capture tiles 2206 in slots 2208 that are provided beneath the caps ofthe “T” cross bars 2204 above the top surface of the extruded tray 2202.The tiles 2206 are thus structurally captured directly in the slots 2208in the extruded tray 2202 to give the extruded tray 2202 sufficientadditional structural strength and integrity to enable it to support thetiles 2206 that are attached thereon.

Referring now to FIG. 22B, therein is shown an isometric view of aportion of the embodiment 2200 with the addition of stops 2210 on theends thereof. The stops 2210, which are located at or across the ends ofthe slots 2208, then capture the tiles 2206 in place and hold them inplace.

Referring now to FIG. 22C, therein is shown a somewhat figurative topview of an alternative configuration for holding the tiles 2206 in placeon the extruded tray 2202. For clarity of illustration, only one “T”cross bar 2204 is shown, so that springs, such as a wire form 2212located therebeneath on the extruded tray 2202, can be more easily seen.The wire forms 2212 then engage or snap into detents 2214 that areformed in corresponding locations in the sides of the tiles 2206 toengage and hold the tiles 2206 in place. The wire forms 2212 then formtray wire springs for the matching tile detent 2214 engagementconfigurations to snap the tiles 2206 in place on the extruded tray2202.

Referring now to FIG. 23, therein is shown an end view of an embodiment2300 in which the tile 2302 itself serves as its own supportingstructure. The tile 2302 thus incorporates a dovetail feature 2304 alongthe sides thereof for interlocking with adjacent tiles 2302. By virtueof the dovetail feature 2304, the tiles 2302 are then able to form astructurally integrated tile matrix. The tiles 2302 also have integralheat sinks 2306 that are oriented vertically on the backs or bottoms ofthe tiles 2302.

In one embodiment, the tiles 2302 are formed as extruded tiles on whichthe LEDs 218 and electrical circuits 2308 are formed on the top surfacesthereof, such as by printing. Thermal grease (not shown) mayadditionally be utilized within the dovetail feature 2304 to ensure goodheat conduction between the tiles 2302.

Referring now to FIG. 24A, therein is shown an isometric view of anembodiment 2400 in which the tiles 2402 are not only self-supporting,but in addition have high rigidity, light weight, substantial stiffness,and high torsional resistance, affording great and consistentco-planarity for the LEDs 218. The tiles 2402, which may be formed of asheet metal construction, have sides 2404 depending at right anglestherefrom. A foot 2406 may be attached to or formed in one or more ofthe sides 2404, and provided with a screw hole 2408 for attaching thetiles 2402 to each other as well as to a supporting substrate, such as adisplay enclosure. An access hole 2410 may be provided in the tile 2402for accessing a screw hole 2408 in an adjacent tile foot 2406.

Referring now to FIG. 24B, therein is shown a side view of an embodiment2412 similar to the embodiment 2400 (FIG. 24A). Embodiment 2412 isattached by screws 2414 to a display shell 2416, such as a displayenclosure. Tiles 2418 in embodiment 2412 may also be provided, asappropriate, with cut-away sides 2420 for attaching PCBs 2422 directlyto the tiles 2418. Alternatively, the PCBs 2422 may be attached to andsupported on the display shell 2416, with the cut-away sides 2420providing clearance for the PCBs 2422.

Referring now to FIG. 24C, therein is shown a side view of an embodiment2424 similar to the embodiment 2400 (FIG. 24A) and the embodiment 2412(FIG. 24B). In the embodiment 2424, the tiles 2426 are attached to eachother by fasteners 2428, such as integrally formed clinch rivet metalfasteners.

Embodiments 2400, 2412, and 2424 (FIGS. 24A, 24B, and 24C, respectively)thus constitute box tiles that have bends that form a multi-sided box.The box tiles are structurally joined to each other to form astructurally integrated, substantially rigid, three-dimensional tilematrix. In one embodiment, a subset of the box tiles is thermally andstructurally attached to an enclosure (e.g., the display shell 2416),and a subset of the box tiles is thermally and supportingly attachedoptionally to one or more electronic circuit boards (e.g., the PCBs2422) that may be conveniently located in one or more cut-away sides2420 of one or more of the box tiles.

Referring now to FIG. 25A, therein is shown an isometric view of anembodiment 2500 in which tiles 2502 are formed, for example byextrusion, as interlockable tiles. In one embodiment, the tiles 2502 areinterlockable extruded tiles that are structurally fitted together tojoin and interlock to each other to form a structurally integrated,rigid, three-dimensional, self-supporting tile matrix structure.

The tiles 2502 have fins 2504 around the periphery thereof that areconfigured in an interlocking geometry, that is, that provide forjoining and interlocking the tiles 2502 to each other. The tiles 2502,in one embodiment, also contain a slot 2506 that passes through thecenter or core of the tile 2502 to reduce the weight of the tile 2502 aswell as increase the air thermal contact convection area and surfacearea thereof for enhanced heat exchange and dissipation. Increasing airthermal contact and improving heat exchange and dissipation can also beprovided by the large surface area of the fins 2504.

Where advantageous, additional elements, such as the spacers 302, can beaccommodated through the slot 2506 as well.

Referring now to FIG. 25B, therein is shown a fragmentary top view of aframe 2508 in which the tiles 2502 have been assembled in interlocked,matrix form. Due to the three-dimensional and interlocking properties ofthe tiles 2502, they are self-supporting, and can be configured anddimensioned to fit together, such as by a press-fit, to form athree-dimensional, self-supporting structural plate. The tile matrix maythen be assembled into the frame 2508 for incorporation into a display.

Referring now to FIG. 25C, therein is shown a partially exploded,fragmentary, isometric view of a display 2510 utilizing the structure ofFIG. 25B. The tiles 2502 have been press-fit together to form athree-dimensional structural plate, and these, in turn, have beenincorporated into the frame 2508.

A reflective sheet 2512 having holes 2514 therein may then be positionedon top of the tiles 2502. The holes 2514 are positioned to match thelocations of the LEDs 218, so that the LEDs 218 then extend upwardlythrough the holes 2514. The reflective sheet 2512 then reflects lightfrom the LEDs 218 upwardly, increasing the brightness of the display2510. In one embodiment, the reflective sheet 2512 is configured as areflective paper layer that is adjacent and substantially surroundingthe individual LEDs 218 on the tiles 2502 to reduce light losstherefrom.

A cover sheet 2516 of suitable transparent material may then be locatedon top of the reflective sheet 2512.

Referring now to FIG. 25D, therein is shown a rear isometric view of thedisplay 2510 attached by a pivot 2518 to a support arm stand assembly2520. In this embodiment, the three-dimensional matrix of the tiles 2502is structurally mounted and interlocked to the frame 2508 of the display2510 to form an integrated, unitized display assembly. The display 2510is thus self-supporting, so that it can be attached directly to thesupport arm stand assembly 2520 through the integral pivot 2518 thereon.

Referring now to FIG. 26, therein is shown a fragmentary sidecross-sectional view of an embodiment 2600 in which tiles 2602 in an LEDtile matrix of a visual display light source are enhanced by LED edgelighting. The LED edge lighting is provided by an edge reflector 2604 onat least one edge, and preferably around the edges 2606, of the LEDtiles 2602. The edge reflector 2604 may be conveniently supported by thetiles 2602 thereadjacent. The edge reflectors 2604 thus reduce dimmingat the edges of a display screen 2608 by reflecting light, originatingfrom the tiles 2602 of the LED tile matrix, back toward the screen 2608.

Referring now to FIG. 27A, therein is shown a fragmentary isometricexploded view of an embodiment 2700 having LED edge lighting that isprovided by an additional LED light bank 2702 that is located at one ormore of the edges 2704 of the tiles 2706 at the perimeter of the LEDtile matrix that forms the visual display light source. The LED lightbanks 2702, in one embodiment, may be directly supported by the tile2706 thereadjacent, such as by a hook-and-slot configuration 2708 formedin the LED light bank 2702 and the tile 2706.

Referring now to FIG. 27B, therein is shown a fragmentary sidecross-sectional view of the structure of FIG. 27A assembled into adisplay 2710. Advantageously, the LED edge lighting that is provided bythe LED light bank 2702 thus provides LEDs 2712 that extend beyond theouter dimensions of a screen 2714 that is being lighted thereby.

Referring now to FIG. 28, therein is shown a flow chart of a displaysystem 2800 with a distributed LED backlight in an embodiment of thepresent invention. The display system 2800 includes providing aplurality of tile LED light sources, each tile LED light source having atile and a plurality of similar LED light sources on each tile connectedfor emitting light therefrom, in a block 2802; orienting the pluralityof tile LED light sources for illuminating a display from the back ofthe display in a block 2804; and integrating the plurality of tile LEDlight sources into a thermally and mechanically structurally integrateddistributed LED tile matrix backlight light source in a block 2806.

It has been discovered that the present invention thus has numerousaspects.

A principle aspect that has been unexpectedly discovered is that thepresent invention enables commercially viable displays for generalconsumption that not only afford the very highest quality, but areeconomical to manufacture, thin, lightweight, strong, and provideefficient light management capability in acceptable form factors andwith acceptable cost.

Another aspect is that wire mazes, bulky circuit boards, heavy and bulkymounts and supports, and complicated heat removal configurations are notnecessary with the present invention.

Another important aspect is that the present invention is thermally andmechanically structurally integrated into a distributed LED tile matrixbacklight light source configuration that enables not onlytwo-dimensional, but even more advantageously, three-dimensionalstructural integration, strength, and integrity.

Another aspect is that the structural integration of the LED lightsources into a thermally and mechanically structurally integrateddistributed LED tile matrix backlight light source provides for formingrows with increased rigidity.

Yet another aspect is that the present invention supports andfacilitates integration of the LED tiles into structurally integratedmulti-row arrays.

Still another aspect of the present invention is that the increasedstrength, rigidity, and integrity provide for readily maintaining arrayflatness.

Another aspect is that the structural integration of the LED lightsources into a thermally and mechanically structurally integrateddistributed LED tile matrix backlight light source provides for greatlyimproved thermal uniformity within and across the extent of the tilematrix backlight light source.

Another aspect is that the present invention is highly compatible withexisting overall CCFL-based display system configurations and formfactors.

Another significant aspect is that the present invention thus enablesLED light source, large-size displays that deliver an excellent,consistent, and affordable consumer experience.

Yet another important aspect is that individual tiles and tile bars canbe qualified before the display is assembled, virtually assuring thatall the LEDs in the display will match and function properly even beforethe display is assembled.

Yet another significant aspect of the present invention is that itvaluably supports and services the historical trend of reducing costs,simplifying systems, and increasing performance.

These and other valuable aspects of the present invention consequentlyfurther the state of the technology to at least the next level.

Thus, it has been discovered that the display system with thedistributed LED backlight of the present invention furnishes importantand heretofore unknown and unavailable solutions, capabilities, andfunctional aspects for display systems with a distributed LED backlight.The resulting processes and configurations are straightforward,cost-effective, uncomplicated, highly versatile and effective, can besurprisingly and unobviously implemented by adapting known technologies,and are thus readily suited for efficiently and economicallymanufacturing large size display devices.

While the invention has been described in conjunction with a specificbest mode, it is to be understood that many alternatives, modifications,and variations will be apparent to those skilled in the art in light ofthe aforegoing description. Accordingly, it is intended to embrace allsuch alternatives, modifications, and variations that fall within thescope of the included claims. All matters hithertofore set forth hereinor shown in the accompanying drawings are to be interpreted in anillustrative and non-limiting sense.

1. A display system comprising: a liquid crystal display subassembly, abacklight assembly comprising multiple tile LED light sources, whereineach tile LED light source comprises multiple light-emitting elements,wherein each tile LED light source is positioned horizontally adjacentto at least one other tile LED light source, wherein the backlightassembly is adapted to transmit light through the liquid crystal displaysubassembly, and a thermal transfer module connected to the backlightassembly and adapted to transfer heat away from the multiple tile LEDlight sources.